From owner-freebsd-questions@FreeBSD.ORG Thu Jun 12 10:35:25 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6B4A11065676 for ; Thu, 12 Jun 2008 10:35:25 +0000 (UTC) (envelope-from daniel_k_eriksson@telia.com) Received: from pne-smtpout2-sn1.fre.skanova.net (pne-smtpout2-sn1.fre.skanova.net [81.228.11.159]) by mx1.freebsd.org (Postfix) with ESMTP id 2623D8FC14 for ; Thu, 12 Jun 2008 10:35:25 +0000 (UTC) (envelope-from daniel_k_eriksson@telia.com) Received: from royal64.emp.zapto.org (195.198.193.168) by pne-smtpout2-sn1.fre.skanova.net (7.3.129) id 4843FAEB001E4CEC; Thu, 12 Jun 2008 12:35:23 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-class: urn:content-classes:message X-MimeOLE: Produced By Microsoft Exchange V6.5.7235.2 Date: Thu, 12 Jun 2008 12:35:22 +0200 Message-ID: <4F9C9299A10AE74E89EA580D14AA10A61A193E@royal64.emp.zapto.org> In-Reply-To: <1a5a68400806080604ped08ce8p120fc21107e7de81@mail.gmail.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: FreeBSD + ZFS on a production server? thread-index: AcjJa9dACWlErCAcSr2DoF9i6VgJqwC/pKjQ References: <1a5a68400806080604ped08ce8p120fc21107e7de81@mail.gmail.com> From: "Daniel Eriksson" To: Cc: =?iso-8859-1?Q?Anders_H=E4ggstr=F6m?= Subject: RE: FreeBSD + ZFS on a production server? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Jun 2008 10:35:25 -0000 Anders H=E4ggstr=F6m wrote: > I plan to install a web server for production use and ZFS looks very > interesting, especially since it has built-in support for RAID and > checksum. ZFS is very nice, but slightly over-hyped imho. However, some of the = hype is warranted and for some use cases ZFS is a much better fit than = UFS. Despite what Wojciech Puchar says, ZFS checksumming can be very useful. = I recently had two drives in a hardware RAID-5 array (8 x 1 TB on a = Highpoint RocketRAID 2340) develop unreadable sectors seemingly at the = same time. I'm not sure what caused it but the end result was a = broken/unavailable array. To make a long story short I managed to get = the drives to remap the bad sectors and bring the array back online. = Since I had ZFS on the array I didn't have to wait for fsck to run = (takes a very long time on a 7 TB array and requires a LOT of memory to = even work), and after the pool had been scrubbed I had a list of files = with bad checksums that I could restore from backup. With UFS I would = have had silent data corruption. Beware, there have been reports of mmap not working properly together = with ZFS. I'm not sure if this is still a problem and if it would affect = a typical web server. It does not seem to affect any of my fileservers = (exporting NFS). /Daniel Eriksson